Simplify the following expression: ${-2-3(-a-7)}$
Answer: Distribute the ${-3}$ into the parentheses: $ -2 {-3(}\gray{-a-7}{)} $ $ -2 + {3a+21} $ Rewrite the expression to group the numeric terms: $ 3a {-2 + 21}$ Combine the numeric terms: $ 3a + {19}$ The simplified expression is $3a+19$